speedmd said:
Hi John
Yes the dual controller is what I will call it from now on. You had a video link showing how it worked a ways back. Will search again for it. The way I understood it, is the first controller runs the motor as normal, then switches to the other controller and other set of 3 phase wires which are wound/timed for a higher RPM. Please correct so I can use the proper terms/ functions.
I wondering how smooth the transition is to the second controller. Also thinking it could tie into a two or three speed hub style tranny ( on and OFF road) possibly in a jack shaft that is separate from the bike gear train for tons of speed range and power every where on the band. Anything like it in a smaller/ narrow motor. If so put me down for one.
Both controllers run all the time on the 6 phase motor. The result is a smoother quieter more efficient motor. It also can be wound to the higher Kv required for scooter hubbie use without going to such low inductance windings that controllers have problems. Plus since both controllers split the current load, a pair cheap controllers is able to outperform a single 3 phase controller of more than double the total price.
No internally geared hub could stand up to the torque of either of our 6 phase motors, but multiple gears aren't needed anyway.
I think you may have looked at some info on our smallest motor, which has 2 speeds. It is 3 phase and just requires one controller. It accomplishes the 2 speeds with a mechanical switching of the windings from series to parallel. The motor essentially has 2 different rpm/volt, one twice as fast as the other. There is no mechanical gearing advantage to low speed, and the controller behaves differently to the 2 different windings, so there is very little difference in torque between high and low. Low does climb hills better, but that's because it is more efficient at low rpm under load than in high.
The stocks of the 2 speed are all but gone. We're working with the factory on 2 different versions of that motor. One would be a lower Kv and made with spoke flanges for a nice little 2 speed bicycle friendly 1500-2kw hubbie that can do both speed and hills. The other version will be a mid-drive specific 8kg outrunner wound to a 50% higher Kv. The thicker windings and lack of a 2 speed switching mechanism that limits max current will make it an 8kg beast capable of extreme power while retaining a low enough Kv for a single reduction straight from the motor to the wheel without going to noisy small diameter drive sprocket.
You're a motorcycle guy, so it baffles me how you're settling for moderate power ebike performance. Sure it's kinda fun since you're so light, but once you stretch the wheelbase a bit lowering the CG and moving it forward, and give yourself a solid 12-15kw of near silent electric power geared for a top speed of about 100kph with a bike that weighs about 50kg, it will be a whole new world for you. Then you'll lose interest in gassers and their unnecessary parts like trannies. Go test drive a Tesla to help gain an understanding of how a tranny isn't necessary. You need an ebike that outruns your buddies' moto's up to moderate traffic speeds.
John